Patients suffering from renal failure of the kidneys are often treated using hemodialysis procedures to remove excess fluid and metabolic wastes (e.g., urea, creatinine, etc.) accumulated in body tissue and blood. During hemodialysis, a patient's blood is shunted from the body through a hemodialysis machine for diffusion and ultrafiltration before being returned to the patient's circulation system. Hemodialysis treatments are typically performed three or perhaps four times per week on a patient having chronic renal failure, with each session lasting between three to five hours.
Patients undergoing hemodialysis treatment are prone to suffer from hypotensive (low blood pressure) symptoms, such as headache, dizziness, muscle cramping and vomiting. Despite the many improvements made to modern hemodialysis procedures, intradialytic hypotension in hemodialysis patients continues to be a major source of concern for the well being of the patient. Many hemodialysis patients experience chronic hypotension, which is abnormal decrease in the patients' blood pressure. For some of these patients, the intradialytic hypotensive symptoms are so severe that they cannot tolerate the hemodialysis procedure and must instead resort to peritoneal dialysis or renal transplant. Indeed, repeated development of these hypotensive symptoms is a key factor leading to the high mortality rate of hemodialysis patients.
For many hemodialysis patients, it is believed that the intradialytic hypotensive symptoms result from the pooling of blood within the internal organs in the abdominal area or waist of the hemodialysis patient. Some have proposed use of an inflatable abdominal band to improve orthostatic hypotension, which is associated with a decrease in systolic blood pressure when patients change from supine to standing position. For instance, N. Yamamoto et al., Treatment of post-dialytic orthostatic hypotension with an inflatable abdominal band in hemodialysis patients, KIDNEY INTERNATIONAL, 70:1793-1800 (Sep. 27, 2006), discloses use of an inflatable abdominal band to treat patients, who after their hemodialysis treatment, are suffering from post-dialytic orthostatic hypotension. H. Tanaka et al., Treatment of orthostatic intolerance with inflatable abdominal band, THE LANCET, 349:175 (Jan. 18, 1997), discloses use of an inflatable abdominal band to treat orthostatic hypotension in patients with orthostatic intolerance. A. Smit et al., Use of lower abdominal compression to combat orthostatic hypotension in patients with autonomic dysfunction, CLIN AUTON RES 14:167-175 (2004), discloses use of an elastic abdominal binding to increase standing blood pressure in patients with neurogenic orthostatic hypotension. J. Denq et al., Efficacy of compression of different capacitance beds in the amelioration of orthostatic hypotension, CLINICAL AUTONOMIC RESEARCH 7, 321-326 (1997), discloses use of compression garments such as an antigravity suit (G suit) in treating patients with chronic symptomatic orthostatic hypotension.
Other types of compressive devices are known in the art. For instance, U.S. Pat. No. 4,925,133 entitled “Hydraulic Buoyancy Force Suit” discloses a buoyancy force suit to reduce pooling of blood with the goal of maintaining consciousness of flying pilots. U.S. Pat. No. 4,534,338 entitled “Servo Operated Anti-G Suit Pressurization System” discloses a servo operated system for quickly pressurizing an aircraft pilot's anti-G suit during high energy maneuvers. U.S. Pat. No. 4,938,208 entitled “Full Length Compressible Sleeve” discloses a sleeve for applying compressive pressure against a patient's limb to prevent pooling of blood in a patient's limb. Similarly, arterial pressure sphygmomanometers include an inflatable compression band worn about a patient's arm to identify diastolic and systolic arterial pressure. Non-inflatable work wear or belts that wrap around a person's waist are used to reduce the load on the back by providing additional support for the spine.
None of these references, however, address treatment of intradialytic hypotension occurring during the hemodialysis treatment. It is, therefore, desirable to reduce the pooling of blood in the abdominal organs of the patient during hemodialysis treatments in order to eliminate the development of intradialytic hypotensive symptoms over the course of hemodialysis.
Patients in critical care may also encounter similar problems resulting from trauma or burns. Reducing the pooling of blood in the abdominal organs of such critical care patients can lead to more effective fluid and blood infusion and improve cardiac filling to enhance cardiovascular functions of these seriously ill patients. Therefore, it is also desirable to reduce the pooling of blood in the abdominal organs of critical care patients to make fluid or blood infusion more effective in improving cardiac filling to enhance cardiovascular functions.